/*******************************************************************************
 * Copyright (c) 2009, 2013 Mountainminds GmbH & Co. KG and Contributors
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Marc R. Hoffmann - initial API and implementation
 *    
 *******************************************************************************/
package org.jacoco.core.runtime;

import java.lang.reflect.Field;
import java.util.Random;

import org.jacoco.core.internal.instr.InstrSupport;

/**
 * Base {@link IRuntime} implementation.
 */
public abstract class AbstractRuntime implements IRuntime {

	/** access to the runtime data */
	protected RuntimeData data;

	public void disconnect(final Class<?> type) throws Exception {
		if (!type.isInterface()) {
			final Field dataField = type
					.getDeclaredField(InstrSupport.DATAFIELD_NAME);
			dataField.setAccessible(true);
			dataField.set(null, null);
		}
	}

	/**
	 * Subclasses must call this method when overwriting it.
	 */
	public void startup(final RuntimeData data) throws Exception {
		this.data = data;
	}

	private static final Random RANDOM = new Random();

	/**
	 * Creates a random session identifier.
	 * 
	 * @return random session identifier
	 */
	public static String createRandomId() {
		return Integer.toHexString(RANDOM.nextInt());
	}

}
